For the first time in a decade, Washington wildlife officials surveyed for a deadly neurological disease during Saturday’s modern deer hunting season opener.
Washington Department of Fish and Wildlife employees and volunteers talked to hunters at check stations and took lymph node samples from any deer killed that day. Those samples will then be sent to a Washington State University lab and tested for chronic wasting disease.
WDFW veterinarian Kristin Mansfield was at a check station near Deer Park. It was a slow day with few hunters stopping and only one CWD sample collected at that check station, she said.
Still, it’s the first step in an effort aimed at, if not stopping, at least slowing the spread of chronic wasting disease. The deadly neurological disease kills deer and elk and is similar to bovine spongiform encephalopathy, or mad-cow disease. There is no known cure, and it’s not known to infect humans, although officials warn against eating the meat of CWD-infected animals. Infected animals will, among other things, stumble, drool, show no fear of people and lose weight.
The disease is spread via “abnormally formed proteins” known as prions. CWD has a long incubation period, meaning seemingly healthy animals may be infected, and prions spread to the soil via deer or elk scat, urine and saliva. CWD in the soil can infect healthy animals years later.
“That’s why this is such a big deal. If it gets into our wild populations, it’s almost impossible to get rid of once it’s already on the landscape,” said Melia DeVivo, an ungulate research scientist with WDFW. “Not to say that we couldn’t try to manage it.”
CWD has not been documented in Washington or Idaho.
However, in 2019 it was confirmed in whitetail deer near Libby, Montana, just miles from the Idaho border. According to research done by DeVivo and others, CWD can decimate wild ungulate populations. As a doctoral student at the University of Wyoming, DeVivo found that CWD can kill up to 19% of a population annually.
Understandably, the confirmation of the disease in Libby has prompted regional worry and, in 2021, the Washington Legislature allocated WDFW $465,000 for CWD surveillance and monitoring.
This year, WDFW is focusing on a handful of Game Management Units in northeast Washington, although Mansfield said the agency hopes to expand surveillance to the entire eastern side of Washington. The goal in 2021 is to take samples from 1,200 animals. Already, WDFW staff have 140 samples from animals believed to have died from the ongoing bluetongue and epizootic hemorrhagic disease outbreak in Washington. EHD and bluetongue are not related to CWD.
Collecting that many samples gives WDFW a 95% chance of detecting CWD if 1% of the wild population is infected, Mansfield said.
“We did get a nice chunk of funding from the Legislature to start our program, but not enough to do our whole plan,” Mansfield said. “We’re keyed into the Libby, Montana, [area] where they have a very high prevalence. Most likely if it comes to Washington it’s going to be from that very close area.”
CWD was first documented in Fort Collins, Colorado, in 1967. Since then, it has spread to at least 25 states and two Canadian provinces. Earlier this month, it was documented in the Teton Wilderness and Greys River watershed, a world-class hunting area in Wyoming south of Yellowstone National Park.
Since the 2019 confirmation of CWD in Libby, Idaho Department of Fish and Game officials in the panhandle region have sampled for CWD yearly, said Micah Ellstrom, the regional biologist in Coeur d’Alene.
“We are sampling again this year,” he said. “Given the proximity of positive detections to the Idaho panhandle, we are sampling annually.”
On average, Idaho spends about $100,000 per year on its CWD detection efforts. In 2018, Idaho banned the importation of deer, elk or moose carcasses from areas with CWD.
The last time Washington had a formal surveillance program was 2011. However, the state banned deer farming in 1995, a move that Mansfield credits with keeping CWD out of Washington. And, like Idaho, Washington has strict rules governing the importation of carcasses from states with documented cases of CWD.
Still, having a solid surveillance system in place is an invaluable tool for wildlife managers, DeVivo said.
“If we’re not looking, we just simply do not know if we have the disease until it’s potentially too late to do anything meaningful to curtail prevalence and help our populations,” she said. “The important part is catching the disease early and doing what we can on the ground to contain it in the area that it’s already present.”